The discovery of wormholes is of great importance to StarFleet. These rare phenomena allow passage between distant regions of space almost instantaneously. Whenever a wormhole is found, it is thoroughly investigated to determine if it is stable and large enough to be used by starships. The vast majority of wormholes are, however, small and unstable.
In 1915, a breakthrough in the human concept of the space-time continuum came when Albert Einstein presented his 'General Theory of Relativity.' This thesis described the space-time continuum in terms of a mathematical statement which became known as 'Einstein's field equation.' A year later, a 'solution' to the field equation was found that appeared to allow for the existence of shortcuts connecting separate locations in space. This was the first time that science had predicted wormholes.
This solution proposed that the shortcut had to exist outside the three dimensions of space and the fourth of time familiar to humans. A good analogy is to imagine a two-dimensional creature that lives on the surface of a sheet of paper. As far as this creature is concerned, depth does not exist. If it wants to travel from the bottom left-hand corner of the paper to the top right, it has to make a journey across the diagonal length of the paper. If the paper were to be folded in such a way that they opposite corners were made to touch, however, the creature could make its journey with one small step it would appear as if these two regions were magically joined together.
A wormhole is almost identical to this principle, but as humans perceive the universe through only three dimensions of space, the curvature must be through another dimension. This means wormholes probably travel through subspace. Often, wormholes can be characterized not just by the subspace disturbance they cause but by their emission of verteron particles. In the Bajoran wormhole artificially created verteron particles allow vessels to travel safely through. Verterons produce a cascade of secondary tunneling particles that are readily detected by starship sensors and can be used to identify wormholes. When an object passes through a wormhole, its arrival can be predicted by elevated neutrino levels.
Another 20th-century theory that helped to advance the understand of wormholes is quantum theory, which posits almost every interaction as an exchange of minuscule, invisible, particles much smaller than an atom. These are known as virtual particles. According to this theory, if it were possible to look at the space-time continuum with a magnifier capable of seeing things over a thousand billion times smaller than an atom, space would contain infinitesimal wormholes that form and collapse all the time.
The comprehension of wormholes made its next great jump with the introduction of a complete theory of quantum gravity in the 21st century. Scientists realized that it was possible to reach into the quantum 'foam' of the space-time continuum and grab one of the tiny wormholes there. In principle it could then be expanded and used for travel. The energy and engineering skills required are, however, beyond even 24th-century science.
Another way to make a wormhole is to purposefully deform an area of the space-time continuum so much that it passes a critical point an deforms a link to another region. This way of constructing the wormhole requires material and equipment to be moved not only through space but also through time. This technology is beyond the Federation's abilities. It is possible that the noncorporeal entities who live in the Bajoran wormhole formed their wormhole in this way. These non-linear creatures are not bound by the concepts of past, present, and future, so they would not be restricted by the boundaries of time travel.
The creation of wormholes can also occur by accident. In 2271, the refitted USS Enterprise NCC-1701 engaged its warp drive before the engines were balanced. The resulting entry into subspace formed a wormhole that temporarily trapped the Enterprise and a nearby asteroid.
Naturally occurring wormholes are rare, and when they are found most are unstable. In 2366, the discovery of the Barzan wormhole created much interest because it appeared to connect the Alpha Quadrant to a far distant region of space. Further investigation showed that it was only semi-stable: the Alpha Quadrant end was fixed, but the other jumped between different locations in an apparently random fashion.
As well as shortcuts through space, wormholes can provide shortcuts through time. In 2371, the USS Voyager NCC-74656 discovered a micro-wormhole that would have sent them several decades back in time if they had passed through it.This article comes from Star Trek Magazine, v. 1, i. 12.